1. Field of the Invention
The present invention relates to a method for fabricating a field emitter electrode, and more particularly to a method for fabricating a field emitter electrode comprising carbon nanotubes by electrolytic copper plating, and a field emission device produced by using the method.
2. Description of the Related Art
Generally, field emission devices are light sources for emitting electrons in a vacuum environment, and use the principle that electrons emitted from fine particles are accelerated by a strong electric field to collide with fluorescent substances, thus emitting light. Such field emission devices provide superior luminous efficiency and are compact and lightweight, compared to light sources for general illuminators such as incandescent lamps. In addition, since field emission devices do not use heavy metals, unlike fluorescent lamps, they have environmentally friendly advantages. For these reasons, field emission devices have drawn attention as next-generation light sources for various illuminators and display devices.
The performance of field emission devices is mainly determined by emitter electrodes capable of emitting fields. Emitter electrodes currently used to improve electron emission properties have an electrode structure wherein carbon nanotubes (CNTs) are uniformly dispersed and are partially exposed to the surface.
FIG. 1 is a flow chart illustrating a conventional method for fabricating a field emitter electrode comprising carbon nanotubes.
Referring to FIG. 1, the conventional method for fabricating an emitter electrode is initiated by coating an electrode material onto a smooth substrate to form an electrode layer (S11). As the substrate, a metal, glass substrate or the like can be used. A paste of carbon nanotubes and a silver powder in the glassy state is prepared using a suitable resin and a solvent, and is then printed onto the electrode layer (S13). After drying, the resulting structure is subjected to an annealing process to remove the resin and the solvent (S15). The annealed structure is subjected to an additional annealing process, followed by taping, to partially expose the carbon nanotubes to the surface (S17), thereby fabricating the final field emitter electrode.
However, the conventional method has a problem that there is difficulty in uniformly dispersing the carbon nanotubes for the preparation of the paste. Due to this problem, the characteristics of the field emitter electrode may be deteriorated. In addition, sufficient physical and mechanical adherence of the paste to the electrode material cannot be achieved by known paste printing processes.
On the other hand, the conventional method requires the use of a substrate on which an electrode material is coated. Accordingly, when the structure of an emitter electrode needs to be modified in order to produce various field emission devices, there may be limitations depending on the kind of the substrate material used. For example, when an emitter electrode is wound in a cylindrical form to produce a rod-shaped field emission device, the use of a common glass or metal substrate makes modification of the structure of the field emission device difficult.